A dog that doesn't want to eat is a sick dog. If he had a high bile acids test and an enlarged liver, that means he has a priXXXXX XXXXXver disease and his liver function is inadequate. This can definitely make a dog feel sick. Your next step needs to be a diagnosis of the KIND of liver problem to see if there is treatment. This is usually done with an ultrasound and a guided biopsy. I guess you have had a CBC and ruled out infection at this point.
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Diagnosis is pretty tough without seeing an animal. To get a diagnosis of a liver problem, there's no way around it, you'll have to get a biopsy of the liver. It definitely sounds like it is liver or gal bladder in nature. You'll have to get more tests to diagnose. The list of hepatobiliary diseases are many. Biopsy will get you an answer.
Best of luck.